**CIGAL Reference Manual, Chapter 6 (RealTime): r_pread**
===== r_pread -- Read byte data from an external input port =====
**        usage: r_pread  opflg eflag ltime  Databuf chan [ nchars flag]**
      Read byte data from an external serial or parallel port. CHAN value 100 is
   printer parallel port, lower values are serial ports (1=COM1, 2=COM2, etc.). 
   NCHARS is the maximum number of bytes to read; if NCHARS is 0, all the bytes currently
   in the buffer are read.
   FLAG can be used to specify reading options (its default value is 0).
  
          FLAG options:
                          1 - wait until NCHARS characters have been read
                                  otherwise reads current available data up to NCHARS bytes
                          2 - return current byte count only (don't read data)
  
    NOTE:  Serial input ports must be configured before being read.
                   To configure the port you should load the configuration bitflag into
                   the COM1 (or COM2) number variable (see COM1[4]).
**See Also:**\\

[[jvs:cigal:manual:chapter6:r_pwrite|r_pwrite]],
[[jvs:cigal|CIGAL Home]], 
[[jvs:cigal:manual|CIGAL Manual]], 
[[jvs:cigal:manual:chapter6|RealTime List]], 
[[jvs:cigal:manual:help|Manual Help]]